• Journal of the Korean Wood Science and Technology
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• 제18권2호
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• pp.36-48
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• 1990

This experiment was carried out to improve the quality of high absorbent polymer which has excellent absorptivity and water retention compared to pulp and absorption sheet, through absorption characteristics-absorptive power, water retention, absorption rate, gel strength, pH, particle size, and moisture content. - of six polymers, namely, anionic polyacrylamide, cationic polyacrylamide, polyacrylic, acid polyvinyle alcohol 500, and 1500, and a-cellulose. and to examine the possibility of substitution of amide groups for carboxyl group and/or hydroxyl group which were commercial high absorbent polymer by comparing the absorption characteristics of the polymers. Polyacrylamide has high absorptive power and water retention, but has low gel strength and poor absorption rate. The rest of polymers were similiar to ${\alpha}$-cellulose in every respect. Thus, polyacrylamides could be replaced with polyacrylic acid and polyvinyl alcohol which are presently a high absorbent polymers. In comparing the absorption characteristics and the absorptive power of the polymers-anionic polyacrylamide, cationic polyacrylamide, polyacrylic acid, polyvinyle alcohol. a-cellulose-the absorptive power was in inverse proportion to the gel strength and absorption rates, affected by the particle size and pH change.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.905-909
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• 2010

Magnetic beads (Dynabeads$^{(R)}$) embedded in ~1 micron size polystyrene beads bearing surface carboxylic acid groups were modified with aminobenzyl ethylenediaminetetraacetic acid (ABEDTA) to concentrate or separate metal ions using pH gradients on micro and nano scales. The immobilization of ABEDTA was achieved by amide formation. The presence of the metal chelating functional group in the fully deprotonated form was confirmed by FT-IR. The chelation efficiency of beads was tested by determining metal ions in supernatant using GFAAS when pH gradients from 3 to 7. Mixtures of Cu and Mg and of Cd and Mn (at 10 ng/mL of metal) were separated as the difference in formation constant with the functional group of ABEDTA. The separation was repeated twice with relative standard deviation of <18%. A polydimethylsiloxane (PDMS) microchip column packed with EDTA-coated magnetic beads was optimized to concentrate metal ion for practical applications by eluting a Cu solution of micro scale at pH 3.

• 한국결정학회지
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• 제8권1호
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• pp.59-63
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• 1997

화합물내에 존재하는 다음 7가지 수소원자의 이상적인 위치들의 한가지 계산법을 보였다. (1) 3급 C-H, (2) 2급 C-H, (3) 1급 C-H, (4) 방향환 C-H와 N-H, (5) 수산기 O-H, (6) 말단평면내의 2개의 수소 (7) 선형인 X-C-H를 갖는 아세틸렌 C-H.

• 농약과학회지
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• 제14권4호
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• pp.456-462
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• 2010

고추 주요 재배지에서 2005년부터 2008년까지 4년에 걸쳐 채집한 180개의 고추 역병균 Phytophthora capsici을 대상으로 carboxylic acid arnide(CAA)계열의 benthiavalicarb, iprovalicarb, dimethomorph에 대한 감수성/저항성 반응을 검정하였다. 실험에 사용한 3가지 살균제에 대한 $EC_{50}$값(병원균의 균사생장을 50% 억제하는 농도)은 benthiavalicarb가 0.033(0.015-0.049) ${\mu}g\;mL^{-1}$, iprovalicarb가 0.411(0.197-0.556) ${\mu}g\;mL^{-1}$, dimethomorph가 0.271(0.101-0.798) ${\mu}g\;mL^{-1}$로 나타났다. Benthiavalicarb와 iprovalicarb는 포장에서 살균제를 사용하기 시작한 2007년부터의 $EC_{50}$값과 사용하기 전의 $EC_{50}$값 간에 차이가 없었으며, 병원균의 $EC_{50}$값에 의한 분포에서도 저항성균의 발현은 찾아볼 수 없었다. Dimethomorph 역시 포장에서 저항성균이 발현하지는 않았지만, 연도별도 병원균의 $EC_{50}$값이 서서히 상승하고 있는 경향을 보여 주었다. 다른 작용기작을 갖는 metalaxyl과의 교차저항성 관계를 구명하기 위하여 $R^2$값을 조사하였는데, benthiavalicarb, iprovalicarb, imethomorph 각각과 metalaxyl과의 $R^2$값은 0.001, 0.009, 0.069로 매우 낮아 전혀 상관관계가 성립하지 않았다. 같은 계열에 속하는 mandipropamid와 실험에 사용한 세 종류의 살균제 각각의 상관관계를 조사한 결과, 유사한 화학구조를 지니는 benthiavalicarb와 iprovalicarb, 그리고 dimethomorph와 mandipropamid간의 상관관계가 인정되었다. 하지만 동일한 CAA계열의 다른 살균제와는 상관관계가 인정되지 않았다.

• 자연과학논문집
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• 제9권1호
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• pp.19-24
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• 1997

PCR 방법을 이용하여 K11 RNA 중합효소를 coding하는 Klebsiella phage gene 1을 cloning 하였고 lac 전사촉진제 조절 하에 발현시켰다. K11 RNA 중합효소는 DAEA-sephacel과 Affigel blue column chromatographies를 사용하는 상용 방법으로 분리하였다. DAEA-sephacel의 0.2-0.3 M $NH_4Cl$ 분획에서 K11 RNA 중합효소의 활성을 보였고, 다음 단계의 Affigel blue column에서 SDS-polyacryl amide gel 상의 단일 band로 분리되었다. K11 RNA 중합효소는 T7 그룹 phage RNA 중합효소로 다른 T7 그룹phage RNA 중합효소와 많은 상동성을 보인다. (대장균 phage T7, T3과 Salmonella tyhimurium phage SP6 RNA 중합효소). 이미 우리는 T7과 SP6 전사촉진제 변이체를 제조한 바 있고 T7과 SP6 RNA 중합효소의 전사촉진제 특이성을 연구한 바 있다 (이상수와 강창원, 1993). K11 RNA 중합효소의 전사촉진제 특이성을 알아보기 위해 SP6 전사촉진제 변이체를 사용하여 in vitro K11 RNA 중합효소의 활성을 측정하였다. 이 변이체 중 K11 전사촉진제와 가장 유사한 것이 가장 높은 K11 RNA 중합효소 활성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.803-808
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• 2010

Poly-${\gamma}$-glutamic acid (${\gamma}$-PGA) is a natural edible polypeptide in which glutamate is polymerized via ${\gamma}$-amide linkages. First, we assessed the eye irritancy potential of ${\gamma}$-PGA in rabbits. Additionally, we studied the effects of ${\gamma}$-PGA on corneal wound healing, due to the anti-inflammatory properties and water retaining abilities of ${\gamma}$-PGA. In this study, the effects of ${\gamma}$-PGA on corneal wound healing after an alkali burn were evaluated. Thirty eyes wounded by alkali burning in 30 white rabbits were divided into three groups: group A was treated with 0.1% 5,000 kDa ${\gamma}$-PGA for 2 days; group B was treated with 0.1% hyaluronic acid; and group C was not treated, as a control. The area of corneal epithelial defect was examined at 12, 24, 30, 36, 42, and 48 h after corneal alkali wounding to determine initial wound healing. We found that ${\gamma}$-PGA promoted corneal wound healing, compared with controls, and showed similar effects to hyaluronic acid. These results indicate that ${\gamma}$-PGA stimulates corneal wound healing by an anti-inflammatory effect and enhancing cell migration and cell proliferation. ${\gamma}$-PGA is a promising biomaterial that may be a substitute for hyaluronic acid in corneal wound healing treatment.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2299-2303
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• 2014

Two diastereoisomers of cyclo(Pro-Tyr) have been synthesized simultaneously. The crystal structures and conformations of both cyclo($\small{L}$-Pro-$\small{L}$-Tyr) and a racemic mixture of cyclo($\small{D}$-Pro-$\small{L}$-Tyr) and cyclo($\small{L}$-Pro-$\small{D}$-Tyr), abbreviated as rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr), have been determined by a single-crystal X-ray diffraction study at low temperature. The crystals of rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr) belong to orthorhombic space group $Pna2_1$ with a = 10.755 (1), b = 12.699 (1), c = 9.600 (1) ${\AA}$ and Z = 4. The tyrosine side chain is folded towards the diketopiperazine (DKP) ring. The DKP ring adopts a twist boat conformation with pseudo symmetry $C_{2v}$. The pyrrolidine ring has an envelope conformation with the N5, C4, C7 and C8 atoms in a plane. The crystal of rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr) is stabilized by hydrogen bonds between amide N2-H2 and carbonyl oxygen O2 in the neighbor. The hydroxyl group of tyrosine residue is also hydrogen bonded to the oxygen of the carbonyl group of the DKP ring in the next molecule. The spectroscopic properties of both isomers are also described.

• Journal of Dental Anesthesia and Pain Medicine
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• 제21권4호
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• pp.337-344
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• 2021

Background: The primary indication for using long-acting anesthetics in dentistry is extensive dental procedures that require pulpal anesthesia beyond 90 min and management of postoperative pain. Ropivacaine is an amide local anesthetic that is available at various concentrations with inherent vasoconstrictive properties at low concentrations. Ropivacaine has a 75% greater margin of safety than bupivacaine. Ropivacaine can be a good alternative to bupivacaine as a local anesthetic in dental implant surgery as it provides a longer duration of both pulpal and soft tissue anesthesia after mandibular nerve block and lowers CNS and cardiovascular toxicity. This study aimed to evaluate and compare the clinical efficacy of ropivacaine and lignocaine for implant surgery anesthesia. Methods: Fifteen patients with bilateral edentulous sites indicated for implant placement were recruited for this study. Patients aged 20-60 years of both sexes were randomly recruited. Thirty implant placements were performed in the test and control groups using ropivacaine and lignocaine with adrenaline as local anesthetics, respectively. Results: The results were analyzed statistically. The duration of anesthesia was significantly higher in the test group than in the control group. Ropivacaine was found to be superior to lignocaine in terms of the quality of anesthesia. The comparison of mean visual analog scale scores showed ropivacaine to have better anesthetic and analgesic effects than the control group. Conclusion: Ropivacaine 0.75% provides a significantly longer duration of anesthesia than lignocaine 2% with adrenaline. Ropivacaine 0.75% decreased intraoperative and postoperative analgesia compared to lignocaine 2% with adrenaline. Hence, ropivacaine 0.75% can be used as an alternative to lignocaine in implant surgeries and other intraoral surgical procedures that require a longer duration of anesthesia and analgesia.

• 농업과학연구
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• 제9권2호
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• pp.576-583
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• 1982

토마토 가공(加工) 공정중(工程中)에 있어서의 유리 아미노산의 변화(變化)를 검토(檢討)할 목적(目的)으로 가공용(加工用)인 KAGOME 77 품종(品種)의 토마토로 조제(調製)한 fresh pulp, heated pulp, puree 및 paste 중(中)의 유리 아미노산을 측정(測定)하여 다음과 같은 결과를 얻었다. 1. Amide group 중(中) glutamine과 asparagine의 분해(分解) 속도(速度)에는 상당(相當)한 차(差)가 인정되었으며, glutamin 은 빨리 분해(分解)되어 paste 중(中)에는 전(全)혀 잔존(殘存)하지 않았으나 asparagine은 paste 중(中)에도 56% 이상(以上)이 잔존(殘存)하였다. 2. 산성(酸性) group중(中)의 glutamic acid의 감소량(減少量)은 전(全) 아미노산 중(中) 가장 컸으며 aspartic acid의 그것은 glutamine 다음인 3 번째로 컸다. Paste 중(中)에 있어서의 glutamic acid와 aspartic acid의 잔존율(殘存率)은 각각 38% 및 24%이었다. 3. 중성(中性) group의 glycine, alanine, valine, isoleucine 및 leucine 등(等)은 약간(若干) 감소(減少)하는 경향(傾向)을 나타내었다. 4. 염기성(鹽基性) group중(中) lysine과 histidin의 변화(變化)는 인정(認定)되지 않았으나, argmme은 가열(加熱) 공정중(工程中)에 약간(若干) 증가(增加)하는 경향(傾向)을 나타내었다. 5. Aromatic group인 tyrosine, phenylalanine 및 tryptophane은 가열(加熱) 공정(工程) 중(中)에는 약간(若干) 증가(增加)하였으나 농축중(濃縮中)에 있어서의 변화(變化)는 거의 인정(認定)되지 않았다. 6. 함유황(含硫黃) 아미노산인 methionine은 전(全) 공정(工程)을 통(通)해서 약간(若干) 감소(減少)하였으나 비단백성(非蛋白性)인 ${\gamma}$ amino butyric acid의 감소(減少)는 거의 인정(認定)되지 않았다. 7. Fresh pulp중(中)의 주요(主要) 아미노산은 glutamic acid>${\gamma}$-amino butyric acid$${\geq_-}$$glutamine>aspartic acid>asparagine의 순(順)으로 많이 함유되어 있었으나, paste 중(中)에는 glutarru acid>${\gamma}$-amino butyric acid>aspartic acid=asparagine의 순(順)으로 많이 함유(含有)되어 있었으며, 미량(微量)이긴 하나 방향족(芳香族) 아미노산과 염기성(鹽基性) 아미노산의 분포비(分布比)가 증가(增加)하는 경향(傾向)을 나타내었다. 8. HITACHI-KLA-5-Amino Acid Analy-zer로 측정(測定)하였을 때 tryptophane의 직전(直前)에 fresh pulp에서는 나타나지 않았던 unknown peak가 가공품(加工品)에 있어서만 나타났으며, 가열(加熱) 및 농축(濃縮)이 진행(進行)됨에 따라 큰 peak로 되었다. 그리고 이것은 lysinoalanine 또는 ornithino이 아니라는 사실(事實)도 확인(確認)하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.441-447
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• 2010

B13, a ceramide analogue, is a ceramidase inhibitor and induces apoptosis to give potent anticancer activity. A series of thiourea B13 analogues was evaluated for their in vitro cytotoxic activities against human renal cancer Caki-2 and leukemic cancer HL-60 in the MTT assay. Some compounds (12, 15, and 16) showed stronger cytotoxicity than B13 and C6-ceramide against both tumor cell lines, and compound (12) gave the most potent activity with $IC_{50}$ values of 36 and $9\;{\mu}M$, respectively. Molecular modeling of thiourea B13 analogues was carried out by comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). We obtained highly reliable and predictive CoMSIA models with cross-validated $q^2$ values of 0.707 and 0.753 and CoMSIA contour maps to show the structural requirements for potent activity. These data suggest that the amide group of B13 could be replaced by thiourea, that the stereochemistry of 1,3-propandiol may not be essential for activity and that long alkyl chains increase cytotoxicity.